1. Field of the Invention
The invention is in the field of user-manipulated toys. More particularly, the invention is an apparatus in the form of a yo-yo that has two side portions that sandwich a center axle onto which the yo-yo's tether is secured. Each of said side portions preferably includes a releasable, disk-shaped rim member. By swapping one set of rim members with another having different characteristics, a user can change the yo-yo's size, shape, weight and/or rim material. This can affect the yo-yo's appearance and/or functionality. Removal of a rim member is preferably easy for a user to accomplish and involves removal of a resilient lock ring and then twisting/rotating the rim member until tabs extending from the rim member are allowed to exit from complementary grooves in a center hub, whereupon the rim member is then free to be removed from the side portion. The invention also relates to an apparatus in the form of a yo-yo that has two side portions connected together by a central axle to which the yo-yo's tether is secured. Each of said side portions preferably includes a replaceable hub portion and a replaceable body portion. Securement of a body portion to a hub portion preferably entails rotating the body portion relative to the hub portion whereupon tabs of the body portion are received within channels of the hub portion. Once the tabs are in place, a gear-type locking mechanism positionally secures said body portion relative to the hub portion.
2. Description of the Related Art
Most yo-yos are in the form of two disk-shaped side portions that are rigidly connected to each other by some form of axle structure. The side portions are usually of a unitary construction in which the rim member is in the form of a continuous outward extension of a hub. Typical materials for yo-yo side portions include plastic, metal or wood. The axle structure is secured to the center of both side portions and may be an assembly of multiple parts, or merely be in the form of a dowel or a riveted pin. In many modern yo-yos, the axle structure includes a center-located spool, bearing or other member that is secured to, and rotatable on, an elongated axle pin.
The axle structure also forms an anchor for one end of a string-type tether. An end-located loop portion of the tether is positioned so that it encircles a center portion of the axle structure. The free end of the tether is usually tied to create a second loop portion that can be placed about one of a user's fingers to thereby secure the yo-yo to the user's hand.
When the tether is wound about the axle structure and the yo-yo is released, or thrown, from a user's hand, the yo-yo will begin to rapidly spin as it moves away from the user's hand and the tether unwinds from the axle structure. Once the tether is fully unwound, the yo-yo may “sleep” at the end of the tether, whereby the yo-yo's side portions continue to spin without the tether rewinding on the axle structure. Once the yo-yo is sleeping, there are a number of tricks, such as “walk the dog,” that a person can perform with the spinning yo-yo. A sleeping yo-yo is also often used to perform tricks that involve temporarily placing the spinning yo-yo onto a portion of the tether intermediate of the tether's two ends.
At the completion of most yo-yo tricks, the user will make a quick tug/jerk on the tether. This will result in a brief tightening of the tether, which is then automatically followed by a temporary slackening of the tether. Once the tether goes slack, the tether's twist will cause one or more portions of the tether located proximate the axle structure to move, and thereby contact, a spinning portion of the yo-yo. Once contact has occurred, the tether portion can become locked to a spinning portion of the yo-yo in a manner whereby rotation of the spinning portion of the yo-yo causes the tether to wind about the axle structure. Winding of the tether on the axle structure makes the yo-yo return to the user's hand.
Over the years, many different shapes have been employed for the yo-yo's side portions. Traditional yo-yos will usually feature substantially planar side portions that have a bulge in the area of the rim to provide an improved weight distribution that increases spin time and stability. Butterfly yo-yos feature side portions that are stretched outwardly, away from the center of the yo-yo, thereby increasing the width of the yo-yo and giving the yo-yo a butterfly shape when viewed in cross-section.
It is also known to use different materials for, or on, the rim member of each of a yo-yo's side portions. For example, while most yo-yos have rim members made of a hard plastic material, it is known to employ rubber either as the rim material, or in the form of an o-ring that is placed on the periphery of each of a yo-yo's side portions.
The different shapes and materials employed in a yo-yo's side portions not only make the yo-yo distinctive, they also affect the yo-yo's performance. For example, a user performing looping tricks with a yo-yo will usually prefer a traditionally shaped yo-yo that has substantially planar side portions. Such a shape is best at looping since the weight distribution is close to the tether's attachment point on the yo-yo, thereby enabling the yo-yo to flip over relatively easily during each loop. For yo-yo tricks in which the user attempts to catch the spinning yo-yo on a medial portion of the tether, a butterfly shaped yo-yo is preferred. The more widely spaced-apart side portions improve the yo-yo's stability whereby the yo-yo is less prone to tilt off the tether. Furthermore, the wider stance of a butterfly-shaped yo-yo facilitates a user being able to land the yo-yo on a medial portion of the tether.
The weight and aerodynamics of the yo-yo's side portions may also affect the yo-yo's ability to sleep for an extended period of time. It is well known that heavier yo-yos can potentially spin for a longer time since the greater weight of their spinning portions increases the yo-yo's rotational momentum. Furthermore, the aerodynamic drag of the yo-yo's spinning portion, a function of the shape and surface contour of the side portions, can affect sleep time since a lower drag allows a yo-yo to sleep longer.
The characteristics of a yo-yo's side portions can also affect the ability of the yo-yo to return on command. The ability for a yo-yo to return on command depends on the tether becoming locked to a spinning portion of the yo-yo. It is well known that a yo-yo's weight can affect a yo-yo's ability to return on command since high weight equates to higher rotational momentum. When the tether goes slack and engages a spinning portion of the yo-yo, the larger the yo-yo's rotational momentum, the larger the engagement force that is required to cause the tether to become locked to said spinning portion of the yo-yo. In other words, the friction generated by a simple glancing contact between the tether and a spinning portion of the yo-yo may be sufficient to cause a light yo-yo to return. However, for a heavier yo-yo, the same contact may only result in the tether sliding on said portion if the friction generated is insufficient to cause the tether to lock onto said spinning portion.
Moreover, the characteristics of the hub or central portion of the yo-yo's side portions can also greatly affect the yo-yo's performance. For example, the hub portion of a yo-yo's side portion will typically feature engagement enhancements on its surface that faces the tether. Furthermore, yo-yos have been made that include an auto-return mechanism in at least one of the yo-yo's hub portions. Said auto-return mechanism normally includes a plurality of centrifugally/centripetally-actuated members that can allow a portion of the axle assembly to freely rotate when the yo-yo is spinning rapidly, and then to be become locked to the side portions when the yo-yo slows down. Once locked, the yo-yo's tether will wrap about said axle portion and thereby cause the yo-yo to return to the user's hand.
To take advantage of the different yo-yo performance characteristics provided through the use of side portions of different shapes and/or materials and/or weights, or that have hub portions that include different features, many experienced yo-yo players will own a large variety of different yo-yos. This enables the player to pick a yo-yo from his or her collection that will work best for the particular trick(s) that the player wishes to perform. However, the costs involved in buying and maintaining a large number of yo-yos can be considerable. In addition, transporting a large number of yo-yos can be bothersome and is usually accomplished using a bulky and expensive transport case specially adapted for carrying yo-yos.
There have also been some prior art yo-yos that employed exchangeable hub portions and rims/body portions. However, said yo-yos have required the user to employ special tools to replace the hubs and rims/body portions and/or the rims/body portions are hard to remove and/or have required complex securement methods and/or lacked a sufficiently positive securement to maintain the hub portions and/or rims/body portions in place should the yo-yo hit a surface or object.